Scott Fisher

iTrader: (28)

If the part numbers are the same, then they have the same timing. Same part= Same part. Remember I am talking about the stock version. I can't speak for the modified version. Why is it so difficult for people to believe that the stock JP FX might be just like a Nova, Rex, Top......... They are the same engines (as long as you get the same production runs.) The only difference is the case. The difference in the cases is what name is molded into it.

Racing4Evo

iTrader: (2)

I can't speak for everyone but I am talking about the modified version. It's a moot point discussing the stock JPs because we already know they're stock like the advertising says.

Regarding the taller heatsink head- It doesn't hurt to have two more fins. What's wrong with wanting to run the engine cooler on a hot day?

InitialD

True. But somehow I never saw the need to have one.

Besides, it's taller CG having 11 fins ! (j/k)

asw7576

What is optimal operating temp for JP engines ? 100C ?

I'm running 120C ( 90% humidity, 34C weather, 42C track temp, maybe less than 50 meter above sea level ).

InitialD

I reality, chasing optimal temp is very difficult. Best method is by sight and sound. Fantini does not tune engines with a temp gun BTW. Nor do a lot of tuners out there...

afm

With those ambient conditions it's Ok to have it at 120ºC.
Actually every engine has it's ideal temp. If your engine is delivering good power and doesn't loose that power over the run of several tanks, and the engine is puffing a good trail of smoke coming out of turns, and the plug's wire is not distorted, and is nice and shiny, then whatever the temp is, thats it.
Most top end engines today like to ruan at 120ºC for optimum power.

AFM

TRAJ

Yes i agree

My engine runs at 118C(244F) in 30C+ heat (Australia) So you engine is correct in temp.

afm

Iagree with you D. This is the best guide I've found and use for Ideal temp search.

What is the ideal engine temperature?

There is no IDEAL temperature for any engine. There are many variables that affect it; Ambient temp, fuel type and nitro content, altitude & barometric pressure, Pipe/manifold type and setting, clutch setting, glow-plug, gear ratio, available traction, How hard your driving, on road or off road Etc. Etc.

All of the following conditions MUST be met before any temperature can be considered correct, assuming the engine is in good shape.
1.-There must be a visible trail of smoke when accelerating from EVERY corner.
2.-The idle is stable.
3.-The glow plug wire stays somewhat shiny and the coil stays round (UN - DISTORTED).
4.-The performance is good.

To know if your engine is properly tuned, you should learn how to read a plug:
1.- Wire and surrounding bottom of plug wet, with like new shiny wire = Rich side of optimum power 85%
2.-Wire and surrounding bottom of plug starting to dry and wire starting to gray = Very close to optimum power 95%
3.-Wire and surrounding bottom of plug dry, wire totally gray but not distorted = Optimum power 100%
4.-Wire and surrounding bottom of plug dry, wire distorted = Slightly lean DANGER!
5.-Wire and surrounding bottom of plug dry, wire broken and distorted or burnt up = Extremely lean POSSIBLE ENGINE DAMAGE!

Actually when a new plug wire just goes slightly gray after a 5 or 10 minute hard run it means your very close to an optimal horsepower tune, but be careful the next step is TOO LEAN!

Note: You can only "Read" your plug in a nearly new state (Wire like new and shiny). A gray plug can still operate well. But after it has totally gone gray performance can start to fall off. To test just put in a new plug and if there is no difference in performance save the gray one or put it back in. If your engine does not feel or run right try a new plug before making major tune change's

AFM

InitialD

I find the most important tell tale thing that says your engine is healthy is by the way the engine idles coming into the pit lane after a few hard runs. It should be low and steady without skipping a beat. Of course it should not idle forever but when the engine comes back in the pits after a hard run, it should idle good and steady. Engine that fires up straight after being very cold and "seem" to idle steady right after that should be very careful. Their low end is probably very lean.

After the engine ilde indicator, I would then go for no. 3, no. 1 and no. 4 in that order as indicators for a good and correct engine tune. Some mod engines can be run rich and yet be as fast if not faster than stock. So performance is quite relative here. As for trail of smoke, not all fuels will exhibit this. Some will give you very little to no smoke at all. Some will give you lots of smoke even at lean conditions. My 2 cents.

Brett.w

Ok have i been racing today and it has been very hot, i have run my JP and i only seem to get 4 mins, i was going to lean it a bit to get more milage but its runnning hot and i dont want to lean it anymore. I have checked the plug and the bottom is brown to going black and the coils is bright silver but it looks "burnt" were it touches the edge (bottom) of the plug.

Any ideas about what to do would be great!

i have tried another engine and it does the same thing.

daniz24

Too many factors :

1. Fuel tank leaks
2. Unbalanced needle setting
3. Clutch setting
4. Fuel's nitro content
5. Engine shimming
6. Engine parts condition
7. Pipe
8. Drive train
9. etc
10. etc

Scott Fisher

iTrader: (28)

I was just "in" superior hobbies (superhobby) ebay store. They have a JP FX12 TO -03W which they call a limited worlds edition engine. Does anybody know what the heck this is. It is available at the rock bottom price of only $465.

For that much money, it should make 2 horsepower and run for 10mins on a tank at only 190 degrees.

Racing4Evo

iTrader: (2)

Sounds like it has all the bells and whistles: Ceramic bearings, and hardened crank.

Scott Fisher

iTrader: (28)

According to the JP website, even the stock version has a hard black crank, but the ceramic bearings would make the engine about that price. That makes sense.

opposite lock

iTrader: (5)

I just got a brand new JP NOVAROSSI 12 S3 MODIFIED and was wondering how they compare to the new JP's?

Are piston & liners etc still available for the older models?

Thanks all.